Ordnance calculating apparatus



ORDNANCE CALCULATING APPARATUS 2 Sheets-Sheet 1 Filed June 1, 1953 NORTH .l I U w l v I In L Z/ P .f F M IFI.

Arnold spl'l'alny ATTOEN Y.

m: b A mzr v NM o m 0 Richard Miner Aug. 23, 1960 c. F. ABT ET AL 2,949,824

ORDNANCE CALCULATING APPARATUS Filed June 1, 1953 2 Sheets-Sheet 2 l NVE N TOES.

Clifford F. Abt Richard Y. Miner" Arnold spi'l'olny BY ATTO NEK.

, 32,949,824 ORDNANCE CALCULATING APPARATUS enema -F. Abt, Long Island City, Richard Y. Miner,

Port Washington, and Arnold :Spitalny, New York,

N.Y., 'assignors-to American Bosch Anna Corporation Filed June 1, I953,Ser.'-N'0. 358,854

SClaim s. (CL 89-41) range of theiprojectile the projectile is automatically fired. The solution=is obtainedfrom input values indicative of t-a'rget position and 'motion, own ship motion,

and the ballistic characteristics of the weapon and projectile.

For a more complete description of the problem and the solution circuit, reference maybe had to the accompan'ying diagramsin which:

Fig. 1 illustrates theproblemaudits-solution withthe target on a straight course;

Fig. 2 illustrates the solution when'the'target is on a curved course; and

Fig. "3 isa schematic diagram of the solution circuit.

The problem involved, and the geometry used in its solution are shown in Fig. 1. An attacking vessel, or own ship 0, is traveling along a course Co at a-specd-So and its observation station x'locates a target submarine E at a relative bearing Br and at a rangeR from x. The

fraction of the target '13 is analyzed by computing appara- 'tus "(not apart of this invention) suchas that described in the copending applications Serial No. 96,688, filed June 2, 1949, for Electro-Mechauical Signalling System, and Serial No. 170,846, new Patent No. 2,745,600, filed June 28, 1950, for Electro-Mechanical Computing Apparatus, both assigncd to the assignee of this invention, 'and it is thereby established that the target is moving on a course C at a speedSat a depth Hq below the surface of the water. Such a computer also indicates "the target angle A, the angle between the path of the target and the line of sight measured cloclcwise from the-target bow, 'and'the curvature of the'target track, Q.

The vessel carries a projectile which has an efiective (fixed) range Re which is-fired from pointy on th'e'vess'el O in 'a'directionadjustable" relatively to the vessel 0, i.e. at a train angle Bgr measured clockwise from-the how. The projectile has-a known time of flight Tf, after which the projectile hits the water and sinks vertically at a rate Sd. The problem therefore is to calculate the -train' angle -Bgr and to'determine theinstant at which the projectile should be launched in order'to score'aihit on the target.

score a hit on the target assuming'thatthefiring operation is initiated at the instant the solution isv given. The

"weapo'n'is always'trained according to the calculated Bgrangle andwhen the calculated advance range R is Patented, Aug. 23, 1960 equal to the efiective range of the projectile Re thefiring circuit is energized automatically.

The projectilehas two components of flight; onecomponent, in the directionof motion of the vessel 0, is 5 equal in length :to SoTf where T is-the time of flight of the projectile while the other component is the calculated R in the direction Bgr. The projectile therefore enters the wateratG which is 'locatedaccording to the vectorial -sum of SoTf and R from the 'point y, and is assumed to sink vertically to "a depth "Hq in the time Td=Hq/Sd. If Tg is'the dead time, or the time elapsed between initiation of firing of the projectile and the actual launching of the projectile, thetotal time elapsed between the initiation of the firing and the arrival of the 'projectilc at depth'H'qds equal to tlie'slim '(Tg-i-'Tf+'-Td) and during this time the target E moves through a-dis- During the dead time Tg, the vessel 0 moves the observation station x along thepath of ownship' for a distance SoTg. The point y,from which the projectile is launched, is located a distance 'P forward of x. Both x and 'y are assumed to been the fore and aft axis of the vessel 0.

Figure 1 shows the geometrical relationship of these values, and from Fig. 1 the'equation's for R and Bgr are obtained as follows:

Equations 3 and 4 can be rewtitten interms of A-and .Br .by expanding cos (A- B7) and si'n (A-- Bz5) 'into-'the LfoIIOWing eqHations: I

and

From these equations it will be seen that R sin Bgr=R sin Bgr+(S(Tg+Tf+Td) and Equations 11 and 12 are the complete equations and reduce to Equations 5 and 6 when the target is on a is the radius of curvature of U and W is the central angle subtended by U. jI-ly is equal to GD==ZZ cos W. Since the length of U is equal to the target travel S(Tg+Tf+Td) and Z=U/W it will be seen that A schematic diagram of the circuit for solving the problem is shown in Fig. 3. It is well known that the successful operation of the motors and electromechanical resolvers requires auxiliary equipment such. as amplifiers, damping devices, filters and phase shifters, for example, and to reduce the complexity of the description these units have been omitted from Fig. 3. t

A two-phase constant alternating voltage supply is available and in Fig. 3 the symbols 11: and are used to represent the two phases.

As used in the following description, the expression a voltage proportional to a quantity is to be interpreted as describing a voltage whose amplitude is proportional to the magnitude of the quantity and the phase of which is shifted by 180 when the sign of the quantity changes.

The valuesof T g+Tf and 1/ Sd for the particular projectile being used are manually inserted into the instrument by displacing the respective shafts 12 and 13 by amounts proportional to these values. Shafts 14, 15, 16, 17, 18 and 19 are displaced angularly according to the respective values of Br, R, A, S Hq and Q (the curvature of the target track) as indicated by the observing and/ or calculating apparatus previously referred to. Since the values of Br, R, A, S, Hq and Q are continuously changing, the shafts 14, 15, 16, 17, 18 and 19 are preferably controlled by servo mechanisms in the well known manner. Provision for manual displacement should sufiice to'describe the invention and hence the servo systems have been omitted in the interest of simplicity.

Shaft 20 is displaced by an amount proportional to S0, and may be servo controlled or displaced manually as desired. Fig. 3 shows provision for manual operation of shaft 20. I

Shaft 12 drives the movable contact 21 of potentiometer 22, the resistance winding 23 of which is energized by 45 so that the voltage output of potentiometer 22 taken between movable contact 21 and one end of resistance winding 23 is proportional in magnitude to T g+T f of the weapon to be fired. Similarly shaft 13 drives the movable contact 24 of potentiometer 25, the

. 4 resistance winding 26 is proportional to l/Sd of the the voltage between movable contact 24 and one end of resistance winding 26 is proportional to 1/Sd of the weapon to be fired.

The primary winding 27 of induction potentiometer 23 is energized by the output voltage of potentiometer 25. The secondary or rotor winding 29 of induction potentiometer 28 is driven by shaft 18 according to Hq so that the voltage induced in secondary winding 29 is proportional to the product of l/Sd and Hg or H q/Sd=Td. The multiplication method of obtaining Td as used and described here is simpler to instrument than a method requiring division of Hq by Sd.

The secondary winding 29 is connected in series with the output terminals of potentiometer 22, and the primary winding 32 of potentiometer 33 so that the voltage energizing primary winding 32 is the algebraic sum of the output voltages of potentiometers 28 and 22. The voltage energizing primary winding 32 is proportional to i- J+ The secondary winding 34 of potentiometer 33 is driven 'by shaft 17 according to S so that the voltage induced in secondary winding 34 is proportional in magnitude to the product S(Tg+Td+Tf). Secondary winding 34 energizes the primary winding 35 of electro mechanical resolver 36 through the closed switch, 37. This condition prevails when the target is pursuing a straightcourse so that shaft 19 is in the zero displacement position and cam 38, driven by shaft 19 opens switch 38' todeenergize relay winding 39. The deenergized relay I winding 39 allows the movable contacts of switches 37 and 40 to be urged to the left by spring 39. The see ondary winding 34 is therefore connected directly to primary winding 35, and at the same time the other primary winding 41 of resolver 36 is deenergized by the short circuiting switch 40.. i

The rotor windings 42 and 43 of resolver 36 are driven according to A by shaft 16 so that the voltages induced in rotor windings 42 and 43 are respectively proportional to S(Tg+Tf+Td) sin A and S(Tg+T;fi -}-Td) cos A.

Shaft 15 drives the secondary or rotor winding 44 of induction potentiometer 45 according to R while the primary or stator winding 44' of potentiometer 45 is energized by e so that the output voltageof rotor winding 44 is proportional to R.

The stator winding 46 of resolver 47 is connected in series with the rotor windings .44 of potentiometer 45 and 43 of resolver 36 so that the voltage energizing stator winding 46 is the algebraic difference between the voltages induced in rotor windings 44 and 43 or the voltage energizing stator winding 46 is proportional to R-S(Tg+Tf|-Td) cos A. The other stator winding 48 of resolver 47 is connected to the rotor winding 42 of resolver 36 and is therefore energized by a voltage proportional to S( Tg-l-T T d) sin A.

The rotor windings 49 and 50 of resolver 47 are displaced angularly by shaft 14 by an amount proportional to Br so that the voltages induced in rotor wiudings49 and 50 are proportional, respectively to:

-Rotor winding 49 is connected to the stator winding 51 of resolver 52 whence the voltage energizing stator winding 51 is proportional to R sin Bgr as will be seen by comparison of Equations 15 and 5.

Rotor winding 50 is electrically connected in series with rotor winding 53 of potentiometer 54, the output terminals-of resistance potentiometer 55, Le. to the end tap 56 of resistor 57 and the movable contact 58, and with the stator winding 59 of resolver 52, so that stator winding 59 is energized by the voltage difference between I the output of rotor winding 50 and the puts-of'potentiometers 54 and 55.

-Thar'otor-winding 53 of potentiometer 54 is displaced according to So by shaft 20, while the stator winding 60 i's enrgized by the ('Tg-j-Tf) output of potentiometer 22 so that the voltage induced in rotor winding 53 is proportional to S(Tg Tf) [The resistance winding 57 of potentiometer 55 is energizedby s' while, the movable contact 58 is displaced along resistor 57 according to the value of the baseline byjadjustment of the knob-and-dial 58' for example, on whichthe'valueof P is indicated, so that the output voltage energizing stator winding 59 is therefore proportional tot which by comparison with Equation 6 is seen to be equal to R cos Bgr.

' The output of rotor winding 61 of resolver 52 energizes the control field winding 62 of motor 63, the main fieldwi'nding, 64 of which is energized by & Motor 63' drives shaft 65 and the rotor windings 61 and 66 of refs'ol'ver52 until the rotor winding 61 is in the null position and the voltage energizing control winding 62 is Zero so that motor 63 stops. Since the stator windings 51- and 59 are energized according to R sin Bgr and R co's Bgr respectively, the position of shaft 65 corresponds to Bgr when the rotor winding 61 is in the null position, and the voltage output of rotor winding 66 is proportional to'R The electrical signal from rotor winding66 is changed into a proportional mechanical displacement by motor 67 in. the usual manner. The controlfield winding 68 of motor 67 is energized by the difference between the voltage output of rotor winding 66 sum of the outand the. voltage output of rotor winding 69 of induction potentiometer 70, the stator winding 71 of which is energized. by The main field winding 67 of motor 67 is. energized by 5 so that motor 67 drives shaft 72 and the rotor winding 69 until the output of rotor winding 69 matches the output of rotor winding 66 and motor 67 stops. 7 1

. In this condition the angular displacement of shaft 72 from itszero position which may be read on dial 72is proportional to R When the solution for R thus obtained-is equal to the known value of Re for the projectile, the firing of the projectile is initiated. A simple device for this purpose may be such as that shown in Fig. 3 for example. 'Shaft 72 drives the input of mechanical differential 73, the other input 74 of which is displaced according to Re and is then locked in the place by means not shown. The output shaft 75 of mechanical differential 73"is displaced according to the difference betweenthe'displacements of shafts 72 and '74 so that when R' fis equal to Re sh-aft 75 is in the zero position. Cam Z6fis driven by shaft 75 and closes switch 77 when, shaft 75 is in the zero position, to cause energization of the firing circuit.

Switch 78 however is connected in series with switch 77 of the firing circuit and is controlled by cam 79 which is driven by shaft 65. Cam 79 closes switch 78 whenever the solution value of Bgr is within the boundaries of safety, and opens switch 78 whenever the value of Bgr is such that the firing of the projectile would cause injury to own ship or personnel.

The description thus far has shown the solution for straight path target travel. If the target is pursuing a curved course, Equations 11 and 12 are by the instrument when the voltage energizing the stator windings 35 and 41 of resolver 36 are proportional to f+ )J' and jI-Iy respectively. It will be seen then that the outputs of rotor windings 42 and 43 of resolver 36 are respectively proportional to Then the voltages energizing stator windings 46 and 48 of resolver 47 are proportional to:

The output voltages of rotor windings 49 and 59 of resolver 47 are respectively proportional to:

Thus the voltages energizing the stator windings 51 and 59 are proportional in magnitude to the right hand side of Equations 11 and 12 and the shafts 65 and 72 are driven to positions corresponding to Bgr and R respectively.

It remains to be shown that the voltage energizing stator windings 35' and 41 are proportional respectively to (S(Tg+Tf+Td)jHx) and jHy.

This is accomplished in the following manner. The S(Tg+Tf-|- Td) output of rotor winding 34 energizes-the stator winding 'of potentiometer 91, the rotor winding 92 of which is displaced by shaft 19 according to Q, the target track curvature, so that the output voltage of rotor winding 92 is proportional to QS(Tg+Tf|-Td) which is equal to W, since Q by definition is equal to l/Z and ZW=S(.Tg|-Tf+Td).

The W signal voltage is changed into a proportional shaft displacement by. motor 93 in the usual manner. Motor 93 drives the shaft 94 and thereby displaces rotor winding 95 of potentiometer 96, the stator winding 97 of which is energized by 41 The rotor winding 92 is connected in series with rotor winding 95 and the difference voltage. energizes the control field winding 98 of motor 93, the main field winding 99 of which is energized by so that motor 93 drives shaft 94 until the voltage output of rotorwinding 95 matches the output of rotor win din'g 92 and themotor 93. is deenergized. In this condition, the displacement of shaft 94 is proportional to W. Shaft '94drives the input shafts of cam units 100 and 1 01, the outputs of which displace the rotor winding's '1'02 and 103 respectively of the potentiometers 104 and 105 proportionally to lsin W/ W) and respectively. The stato'rwindings .106 and 107 of potentiometer's 1'04 and 105 are energized by theoutput of rotor winding 34 so that the output voltages of rotor windings 102 and 103 are respectively:, S(Tg+Tf+ Td)(1sin W/W) =jHx, according to Equation 13 and =jHy, according to Equation 14 When the target is on a curved course, Q is not zero so that cam 38 closes switch 38 to thereby energize the relay winding 39 which urges the movable contacts of switches 37 and 40 to the right against the action of spring 39. Actuation of the movable contact of switch 37 to the right connects rotor winding 102 in series with 7 rotor winding 34 and stator winding 102 in series with rotor winding 34 and stator winding 35 so that the volt age energizing stator winding 35 is the algebraic difierence between the outputs of rotor windings 34 and 102 or is proportional to:

Actuation of the movable contact of switch 40 to the right connects the output of rotor winding 103 to the stator winding 41 which is therefore energized by a voltage proportional to fHy.

It will be seen that the instrument then will present a solution according to these values which is the curved course solution.

1. In a device of the character described-for indicating train angle and controlling the fin'ng of a trainable weap on with a fixed range projectile, a trainable weapon, a vehicle, said weapon being carried by said vehicle, means for training said weapon with respect to said vehicle, said means comprising, means for calculating a range and bearing according to present own vehicles position and motion and target position and motion such that a projectile fired at the present instant will reach the target, means for training said weapon according to said bearing, means for comparing said calculated range with the known effective range of the projectile and means controlled by the output of said comparing means to launch the projectile when the calculated and effective ranges are equal.

2. In a device of the character described for indicating train angle and controlling the firing of a trainable weapon with a fixed range projectile, a trainable weapon, a vehicle, said weapon being carried by said vehicle, means for training said weapon with respect to said vehicle, said means comprising, means for calculating a range and bearing according to present own vehioles position and motion and target position and motion such that aprojectile fired at the present instant will reach the target, means for training said weapon according to said bearing, means for comparing said calculated range with the known effective range of the projectile and switch means controlled by the output of said comparing means to launch the projectile when the calculated and efiective ranges are equal.

3. In an ordnance calculating apparatus for indicating train angle and controlling the firing of a trainable Weapon with a fixed range projectile, a trainable weapon, a vehicle, said weapon being carried by said vehicle, means for training said weapon with respect to said vehicle, said means comprising, an electro-mechanical means for calculating a range and bearing according to present own vehicles position and motion and target position and motion such that a projectile fired at the present instant will reach the target, means for training said weapon according to said bearing, electron-mechanical means for comparing said calculated range with the known efiective range of the projectile and switch'means controlled bythe output of said comparing means whereby said projectile is launched when the calculated and effective ranges are equal. 4

4. In a device of the character described for indicating train angle and controlling the firing of a trainable weapon with a fixed range projectile, a source of voltage, a first potentiometer energized thereby, a second source of voltage, a second potentiometer, series connections between said first and second sources of voltage andtsaid second potentiometer, a resolver having a pair of primary and a pair of secondary windings relatively rotatable, one primary winding of said resolver being energized by said second potentiometer output, a second resolver, having series connections between the secondary windings of said first resolver of the primary windings of said second resolver, a third resolver having series connections between the output of said first potentiometer, one of the secondary windings of said second resolver and one of the primary windings of said third resolver, series connections between the other secondary winding of said second resolver and the other primary winding of said third resolver, motive means energized by the output of said third resolver, secondary winding and an operative connection between said motive means and .the rotor of said third resolver whereby said secondary winding is driven to null position.

5. In a device of the character described, a first and a second source of voltage, a first potentiometer energized by said first source of voltage, a second potentiometer, series connections between said sources of voltage and said second potentiometer, three resolvers, the first of said resolvers having a pair of primary and a pair of secondary windings relatively rotatable with one of said primary windings energized by the output of said second potentiometer, said second resolver having series connections between the secondary winding of said first resolver and the primary windings of said second resolver, said third resolver having series connections between the output of said first potentiometer, one of said secondary windings of said second resolver and one of the primary windings of said third resolver, series connections between the other secondary winding of said second resolver and the other primary winding of said third resolver, motive means energized by the output of the secondary winding of said third resolver and an operative connection between said motive means and the rotor of said third resolver whereby the secondary winding of said third resolver is driven to null position.

References Cited in the file of this patent UNITED STATES PATENTS 2,402,024 Crooke June 11, 1946 2,488,448 Townes Nov. 15, 1949 2,733,436 Doba Jan. 31, 1956 

